AN ELEVATOR

Abstract

An elevator built in place of an earlier elevator in an elevator shaft or equivalent. In the elevator, the elevator car is suspendended by means of hoisting ropes consisting of a single rope or several parallel ropes. The elevator has a traction sheave which moves the elevator car by means of the hoisting ropes. The elevator has rope portions of the hoisting ropes going upwards and downwards from the elevator car, and the rope portions going upwards from the elevator car are under a first rope tension (T1) which is greater than a second rope tension (T2), which is the rope tension of the rope portions going downwards from the elevator car, and the elevator has been built in place of an earlier elevator mounted in the elevator shaft or equivalent or by making modifications in the earlier elevator.

Full Text

AN ELEVATOR
The present invention relates to an elevator.
One of the objectives in elevator development work is
to achieve efficient and economical utilization of
building space. In recent years, this development work
has produced various elevator solutions without ma-
chine room, among other things. Good examples of ele-
vators without machine room are disclosed in specifi-
cations EP 0 631 967 (A1) and EP 0 631 968. The eleva-
tors described in these specifications are fairly ef-
ficient in respect of space utilization as they have
made it possible to eliminate the space required by
the elevator machine room in the building without a
need to enlarge the elevator shaft. In the elevators
disclosed in these specifications, the machine is com-
pact at least in one direction, but in other direc-
tions it may have much larger dimensions than a con-
ventional elevator machine.
In these basically good elevator solutions, the space
required by the hoisting machine limits the freedom of
choice in elevator lay-out solutions. Space is needed
for the arrangements required for the passage of the
hoisting ropes. It is difficult to reduce the space
required by the elevator car itself on its track and
likewise the space required by the counterweight, at
least at a reasonable cost and without impairing ele-
vator performance and operational quality. In a trac-
tion sheave elevator without machine room, mounting
the hoisting machine in the elevator shaft is often
difficult, especially in a solution with machine
above, because the hoisting machine is a sizeable body
of considerable weight. Especially in the case of lar-
ger loads, speeds and/or hoisting heights, the size
and weight of the machine are a problem regarding in-
stallation, even so much so that the required machine
size and weight have in practice limited the sphere of
application of the concept of elevator without machine
room or at least retarded the introduction of said
concept in larger elevators. In modernization of ele-
vators, the space available in the elevator shaft of-
ten limits the area of application of the concept of
elevator without machine room, in many cases, espe-
cially when hydraulic elevators are to be modernized
or replaced, it is not practical to apply the concept
of roped elevator without machine room due to insuffi-
cient space in the shaft, especially in a case where
the hydraulic elevator solution to be modern-
ized/replaced has no counterweight. A disadvantage
with elevators provided with a counterweight is the
cost of the counterweight and the space it requires in
the shaft. Drum elevators, which are nowadays rarely
used, have the drawbacks of heavy and complex hoisting
machines with a high power/torque requirement. Prior-
art elevator solutions without counterweight are ex-
otic, and no adequate solutions are known. Before, it
has not been technically or economically reasonable to
make elevators without a counterweight. One solution
of this type is disclosed in specification WOO9806655.
A recent elevator solution without counterweight pre-
sents a viable solution. In prior-art elevator solu-
tions without counterweight, the tensioning of the
hoisting rope is implemented using a weight or spring,
and this is not an attractive approach to implementing
the tensioning of the hoisting rope. Another problem
with elevator solutions without counterweight, when
long ropes are used e.g. due to a large hoisting
height or a large rope length required by high suspen-
sion ratios, is the compensation of the elongation of
the ropes and the fact that, due, to rope elongation,
the friction between the traction sheave and the
hoisting ropes is insufficient for the operation of
the elevator. In a hydraulic elevator, especially a
hydraulic elevator with lifting force applied from be-
low, the shaft efficiency, in other words the ratio of
the cross-sectional shaft area occupied by the eleva-
tor car to the total cross-sectional area of the ele-
vator shaft, is fairly high. This has traditionally
been a significant factor contributing towards the
choice of a hydraulic elevator as the elevator solu-
tion for a building. On the other hand, hydraulic ele-
vators have many drawbacks associated with their lift-
ing mechanism and oil consumption. Hydraulic elevators
consume plenty of energy, possible oil leakages from
the elevator equipment is an environmental risk, the
required periodic oil changes constitute a large cost
item, even an elevator installation in good repair
produces unpleasant smell as small amounts of oil es-
cape into the elevator shaft or machine room and from
there further into other parts of the building and
into the environment and so on. Because of the shaft
efficiency of the hydraulic elevator, its moderniza-
tion by replacement with another type of elevator that
would obviate the drawbacks of a hydraulic elevator
while necessarily involving the use of a smaller ele-
vator car is not an attractive solution to the owner
of the elevator. Also, the small machine spaces of hy-
draulic elevators, which may be located at a large
distance from the elevator shaft, make it difficult to
change the elevator type.
There are a very large number of traction sheave ele-
vators installed and in use. Such traction sheave ele-
vators were built in their time in accordance with the
users" needs as conceived at the time and the intended
uses of the buildings in question. Afterwards, both
users" needs and the uses of the buildings have
changed in many cases, and an old traction sheave ele-
vator may have proved to be insufficient in respect of
car size or otherwise. For example, older and rela-
tively small elevators are not necessarily suited for
the transportation of prams or wheelchairs. On the
other hand, in older buildings which have been con-
verted from residential use for office or other uses,
a smaller elevator installed in its time is no longer
sufficient in respect of capacity. As is known,
enlarging such a traction sheave elevator is practi-
cally impossible because the elevator car and the
counterweight already take up the cross-sectional area
of the elevator shaft and there is no reasonable way
of enlarging the car.
The object of the invention in general is to achieve
at least one of the following objectives. On the one
hand, it is an aim the invention to develop the eleva-
tor without machine room further so as to allow more
effective space utilization in the building and eleva-
tor shaft than before. This means that the elevator
must be so constructed that it can be installed in a
fairly narrow elevator shaft if necessary. One objec-
tive is to achieve an elevator in which the hoisting
rope has a good grip/contact on the traction sheave.
Yet another objective is to achieve an elevator solu-
tion without counterweight without compromising the
properties of the elevator- A further objective is to
eliminate the adverse effects of rope elongations. It
is an objective of the invention to create a method
for replacing or modernizing a hydraulic elevator
with/into a rope-driven elevator without reducing or
at least without substantially reducing the size of
the elevator car. It is an objective of the invention
to enable a rope-driven elevator to be modernized into
an elevator with a clearly larger car or to be re-
placed with an elevator with a larger car than before.
The object of the invention should be achieved without compromising the possibility
of varying the basic elevator layout.
Accordingly, the present invention provides an elevator, in which elevator the
elevator car is suspended by means of hoisting ropes consisting of a single rope
or several parallel ropes, said elevator having a traction sheave which moves the
elevator car by means of the hoisting ropes, characterized in that the elevator has
rope portions of the hoisting ropes going upwards and downwards from the
elevator car, and the rope portions going upwards from the elevator car are under
a first rope tension (T1) which is greater than a second rope tension (T2), which is
the rope tension of the rope portions going downwards from the elevator car, and
that the elevator has been built in place of an earlier elevator mounted in an
elevator shaft or equivalent or by making modifications in the earlier elevator, the
arrangement being such that the elevator roping is provided with a compensating
system for maintaining a substantially constant ratio (T1/T2) between the rope
forces acting in upward and downward directions.
The present invention also provides a method of forming an elevator in place of an
earlier elevator mounted in an elevator shaft or equivalent or by making
modifications in the earlier elevator, the method involving the steps of replacing
the hoisting function of the earlier elevator by a hoisting function comprising a set
of hoisting ropes, said set of hoisting ropes having one rope or a plurality of
parallel ropes, and an elevator machine driving the hoisting ropes, connecting the
elevator car of the elevator to be formed to the hoisting ropes such that the
elevator has rope portions going downwards and upwards from the elevator car;
and providing the elevator roping with a compensating system for maintaining a
substantially constant ratio (T1/T2) between the rope forces acting in upward and
downward directions.
Preferably, the earlier elevator is a hydraulically lifting elevator or a traction sheave
elevator. Preferably, the elevator car of the elevator has a larger floor area than
the earlier elevator. Preferably, the elevator is an elevator without counterweight.
In a preferred embodiment, the elevator has a compensating mechanism
comprising a lever, a set of tensioning sheaves or compensating sheaves. The
compensating mechanism may comprise one and/or more diverting pulleys.
Preferably, the continuous contact angle between the traction sheave and the
hoisting ropes is at least 180°. Preferably, the hoisting ropes used are high-
strength hoisting ropes and have diameters smaller than 8 mm, preferably
between 3-5 mm. Preferably, the hoisting machine is particularly light in relation
to the load. Preferably, the traction sheave is coated with polyurethane, rubber or
some other frictional material suited to the purpose. The traction sheave, at least
in the area of the rope grooves, is made of metal, preferably cast iron, and
preferably has undercut rope grooves. The D/d ratio of the diverting pulleys below
the elevator car is below 40.
Preferably, the replacing hoisting function is installed in place of a hydraulic
hoisting function. The replacing hoisting function may be installed in place of a
traction sheave-operated hoisting function comprising a counterweight. The
replacing hoisting function may be installed in place of a hoisting function
implemented using a drum, a screw or another corresponding hoisting function.
Preferably, the equipment comprised in the hoisting function of the earlier elevator
is removed from the elevator shaft or equivalent. Preferably, a replacing elevator
car of a size larger than the earlier elevator car is formed in the elevator shaft or
equivalent.
Inventive embodiments are also discussed in the description sec-
tion of the present application. The inventive content
of the application can also be defined differently
than in the claims below. The inventive content may
also consist of several separate inventions, espe-
cially if the invention is considered in the light of
expressions or implicit sub-tasks or from the point of
view of advantages or categories of advantages
achieved. Therefore, some of the attributes contained
in the claims below may be superfluous from the point
of view of separate inventive concepts. For example,
the equipment comprising the main components of the
elevator to be installed in place of the earlier ele-
vator, or the equipment designed for modernization of
the hoisting system of the earlier elevator, the
equipment comprising the machinery, ropes and divert-
ing pulleys needed for the hoisting function and ac-
cessories for the installation of these, and possibly
also the elevator car and guide rails, is an inventive
whole together with an instruction to replace or alter
the elevator at least in respect of the hoisting func-
tion so as to make it consistent with the present ap-
plication.
By applying the invention, one or more of the follow-
ing advantages, among others, can be achieved:
— Due to a small traction sheave, an elevator and/or
elevator machine of a fairly compact size are/is
achieved
— A good traction sheave grip, which is achieved in
particular by using Double Wrap roping, and light-
weight components allow the weight of the elevator
car to be considerably reduced.
— A compact machine size and thin, substantially
round ropes permit the elevator machine to be rela-
tively freely placed in the shaft. Thus, the eleva-
tor solution of the invention can be implemented in
a fairly wide variety of ways in the case of both
elevators with machine above and elevators with ma-
chine below.
— The elevator machine can be advantageously placed
between the car and a shaft wall.
— All or at least part of the weight of the elevator
car can be carried by the elevator guide rails.
— Applying the invention allows effective utilization
of the cross-sectional area of the shaft. Thus,
e.g. a hydraulic elevator can be modernized into a
rope-driven elevator or replaced in the same shaft
with a rope-driven elevator without reducing the
size of the elevator car, or an old traction sheave
elevator can be replaced with or modernized into a
larger elevator.
— The light, thin ropes are easy to handle, allowing
considerably faster installation.
— E.g. in elevators for a nominal load below 1000 kg,
the thin and strong steel wire ropes of the inven-
tion have a diameter of the order of only 3-5 mm,
although thinner and thicker ropes may also be
used.
— With rope diameters of about 6 mm or 8 mm, fairly
large and fast elevators according to the invention
can be achieved.
— Either coated or uncoated ropes can be used.
— The use of a small traction sheave makes it possi-
ble to use a smaller elevator drive motor, which
means a reduction in drive motor acquisi-
tion/manufacturing costs.
— The invention can be applied in gearless and geared
elevator motor solutions.
— Although the invention is primarily intended for
use in elevators without machine room, it can also
be applied in elevators with machine room.
— In the invention, a better grip and a better con-
tact between the hoisting ropes and the traction
sheave are achieved by increasing the contact angle
between them.
— Due to the improved grip, the size and weight of
the car can be reduced.
— The space saving potential of the elevator of the
invention is increased considerably as the space
required by the counterweight is at least partially
eliminated.
— As a result of the lighter and smaller elevator
system, energy savings and at the same time cost
savings are achieved.
— The placement of the machine in the shaft can be
relatively freely chosen as the space required by
the counterweight and counterweight guide rails and
roping can be used for other purposes
— By mounting at least the elevator hoisting machine,
the traction sheave and a rope sheave functioning
as a diverting pulley in a complete unit, which is
fitted as a part of the elevator of the invention,
considerable savings in installation time and costs
will be achieved.
— In the elevator solution of the invention, it is
possible to dispose all ropes in the shaft on one
side of the elevator car; for example, in the case
of rucksack type solutions, the ropes can be ar-
ranged to run behind the elevator car in the space
between the elevator car and the back wall of the
elevator shaft.
— The invention makes it easy to implement scenic-
type elevator solutions as well.
— Since the elevator solution of the invention does
not necessarily comprise a counterweight, it is
possible to implement elevator solutions in which
the elevator car has doors in several walls, in an
extreme case even in all the walls of the elevator
car. In this case, the car guide rails of the ele-
vator are disposed at the corners of the elevator
car.
— The elevator solution of the invention can be im-
plemented with several different machine solutions.
— The suspension of the car can be implemented using
almost any suitable suspension ratio.
— Compensation of rope elongations by means of a com-
pensating system according to the invention is a
cheap and simple structure to implement.
— Compensation of rope elongations by means of a lever
is a cheap and light structure.
— Using the rope elongation compensation solutions of
the invention, it is possible to achieve a constant
ratio between the forces T1/T2 acting on the trac-
tion sheave.
— The ratio between the forces T1/T2 acting on the
traction sheave is independent of the load.
— By using the rope elongation compensating system of
the invention, unnecessary stress on the machine and
ropes can be avoided.
— By using the rope elongation compensating solutions
of the invention, the relation between the forces
T1/T2 can be optimized to achieve a desired value.
— The solutions of the invention for compensating rope
elongation are safe solutions which make it possible
to guarantee the required friction / contact between
the traction sheave and the hoisting rope in all
situations.
— In addition, the rope elongation compensating solu-
tions of the invention make it unnecessary to stress
the hoisting ropes in order to ensure friction be-
tween the traction sheave and the hoisting rope by
loads larger than necessary, and consequently the
useful life of the hoisting ropes is increased and
their damage susceptibility is reduced.
— When rope elongation is compensated using the ar-
rangement of the invention for compensating rope
elongation with compensating sheaves of different
diameters, it will be possible using this solution
to compensate even very large rope elongations, de-
pending on the diameters of the pulleys used.
— By using a rope elongation compensating solution ac-
cording to the invention in which the compensating
apparatus used is a differential gear, it is possi-
ble to compensate even large rope elongations, espe-
cially in the case of high hoisting heights.
The primary area of application of the invention is
elevators designed for the transportation of people
and/or freight. A typical area of application of the
invention is in elevators whose speed range is about
1.0 m/s or below but may also be higher. For example,
an elevator having a traveling speed of 0.6 m/s is
easy to implement according to the invention.
In both passenger and freight elevators, many of the
advantages achieved through the invention are pro-
nouncedly brought out even in elevators for only 2-4
people, and distinctly already in elevators for 6-8
people (500 - 63 0 kg).
According to the invention, when an elevator, e.g. a
hydraulic elevator or traction sheave elevator, is to.
be modernized or replaced, the existing elevator is
removed partly or completely and a new elevator is
formed, wherein the elevator car is suspended on a set
of continuous hoisting ropes comprising rope portions
going upwards from the elevator car and downwards from
the elevator car. The new elevator to be set up is a
traction sheave elevator, which is preferably imple-
mented completely without counterweight. The old
hoisting function is always removed from service,
preferably also removed physically, which means that,
for example in the case of a hydraulic elevator, the
hydraulic cylinder and hydraulic machine are removed
from the elevator or that, in the case of a traction
sheave elevator, the old hoisting ropes, hoisting ma-
chine and counterweight are removed. The same elevator
car or an enlarged or new elevator car is suspended on
a new set of hoisting ropes, which can be installed
while the old hoisting function is being removed or as
a separate installation operation. A hydraulic eleva-
tor lifted from below or a corresponding hydraulic
elevator can be easily converted into a roped elevator
without having to reduce the size of the elevator car.
When a so-called roped hydraulic elevator is to be re-
placed or modernized, the invention makes it possible
to use a somewhat larger elevator car because, instead
of a hydraulic cylinder placed at the side of the ele-
vator car, only a space for the hoisting ropes is
needed. When a traction sheave elevator is to be mod-
ernized or replaced, the invention already allows a
clearly larger elevator car to be used, because the
share of the shaft width required for the counter-
weight and counterweight guide rails, either laterally
or towards the back wall, becomes available for accom-
modating a larger elevator car. Thus, for example, an
elevator for 6 persons can be replaced with an eleva-
tor for 8 persons, or an elevator for 8 persons can be
replaced with an elevator for 10 persons. The inven-
tion is also applicable for use in connection with
larger elevators, although the most suitable range of
application is elevators conventionally used in resi-
dential and office buildings, i.e. elevators designed
for a nominal load of about 1000 kg or less. The ele-
vator modernisation or "full replacement" according to
the invention is accomplished by replacing or modern-
izing an elevator installed in an elevator shaft or
equivalent, e.g. in a partially open space located at
the side of a building yet delimiting the elevator in
respect of placement. In general, modernization pri-
marily means modernizing the hoisting function and
secondarily increasing the car size. The motive for
modernization may consist of one or both of the above-
mentioned reasons or some other reason. When an eleva-
tor is to be replaced, generally the car and the
hoisting function are replaced. Heavy modernization of
an elevator system or nearly complete replacement of
the old elevator system are in many cases mutually al-
ternative due to economic factors.
In the elevator of the invention, normal elevator
hoisting ropes, such as generally used steel wire
ropes, are applicable. In the elevator, it is possible
to use ropes made of artificial materials and ropes in
which the load-bearing part is made of artificial fi-
ber, such as e.g. so-called "aramid ropes", which have
recently been proposed for use in elevators. Applica-
ble solutions also include steel-reinforced flat
ropes, especially because they allow a small deflec-
tion radius. Particularly well applicable in the ele-
vator of the invention are elevator hoisting ropes
twisted e.g. from round and strong wires. From round
wires, the rope can be twisted in many ways using
wires of different or equal thickness. In ropes well
applicable in the invention, the wire thickness is be-
low 0.4 mm on an average. Well applicable ropes made
from strong wires are those in which the average wire
thickness is below 0.3 mm or even below 0.2 mm. For
instance, thin-wired and strong 4 mm ropes can be
twisted relatively economically from wires such that
the mean wire thickness in the finished rope is in the
range of 0.15 ... 0.25 mm, while the thinnest wires may
have a thickness as small as only about 0.1 mm. Thin
rope wires can easily be made very strong. In the in-
vention, rope wires having a strength greater than
about 2000 N/mm2 can be used. A suitable range of rope
wire strength is 2300-2700 N/mm2. In principle, it is
possible to use rope wires having a strength of up to
about 3000 N/mm2 or even more.
The elevator of the invention, in which the elevator
car is suspended by means of hoisting ropes consisting
of a single rope or a number of parallel ropes, said
elevator having a traction sheave which moves the ele-
vator car by means of the hoisting ropes, has rope
portions of the hoisting ropes going upwards and down-
wards from the elevator car, and the rope portions go-
ing upwards from the elevator car are under a first
rope tension (T1) which is greater than a second rope
tension (T2) , which is the rope tension of the rope
portions going downwards from the elevator car. In ad-
dition, the elevator comprises a compensating system
for keeping the ratio (T1/T2) between the first rope
tension and the second rope tension substantially con-
stant .
In the method of the invention for forming an eleva-
tor, the elevator car is connected to the elevator
roping used to hoist the elevator car, said roping
consisting of a single rope or a plurality of parallel
ropes and comprising rope portions going upwards and
downwards from the elevator car, and that the elevator
roping is provided with a compensating system for
keeping the ratio (T1/T2) between the rope forces act-
ing in upward and downward directions substantially
constant.
By increasing the contact angle by means of a rope
sheave functioning as a diverting pulley, the grip be-
tween the traction sheave and the hoisting ropes can
be increased. In this way, the car can be made lighter
and its size can be reduced, thus increasing the space
saving potential of the elevator. A contact angle of
over 180° between the traction sheave and the hoisting
rope is achieved by using one or more diverting pul-
leys . The need to compensate the rope elongation
arises from the friction requirements, to ensure that
a grip sufficient for operation and safety of the ele-
vator exists between the hoisting rope and the trac-
tion sheave. On the other hand, it is essential in re-
spect of elevator operation and safety that the rope
portion below the elevator car in an elevator solution
without counterweight should be kept sufficiently
tight. This can not necessarily be achieved using a
spring or a simple lever.
In the following, the invention will be described in
detail by the aid of a few examples of its embodiments
with reference to the accompanying drawings, wherein
Fig. 1 is a diagram representing a traction sheave
elevator without counterweight according to
the invention
Fig. 2 presents diagram of another traction sheave
elevator without counterweight according to
the invention,
Fig. 3 presents a diagram of a third traction sheave
elevator without counterweight according to
the invention,
Fig. 4 presents a diagram of a fourth traction
sheave elevator without counterweight accord-
ing to the invention,
Fig. 5 presents a diagram of another traction sheave
elevator without counterweight according to
the invention,
Fig. 6 presents a diagram of another traction sheave
elevator without counterweight according to
the invention,
Fig. 7 presents a diagram of another traction sheave
elevator without counterweight according to
the invention,
Fig. 8 presents a diagram of another traction sheave
elevator without counterweight according to
the invention,
Fig. 9 presents a diagram of another traction sheave
elevator without counterweight according to
the invention,
Figures 10 present solutions in which an earlier ele-
vator layout has been replaced with a solu-
tion according to the invention.
Fig. 1 presents a diagrammatic illustration of the
structure of an elevator according to the invention.
The elevator is preferably an elevator without machine
room, with a drive machine 4 placed in an elevator
shaft. The elevator shown in the figure is a traction
sheave elevator without counterweight and with machine
above. The passage of the hoisting ropes 3 of the ele-
vator is as follows: One end of the ropes is immovably
fixed to a fixing point 16 on a lever 15 fastened to
the elevator car 1, said fixing point being located at
a distance a from the pivot 17 connecting the lever to
the elevator car 1. In Fig. 1, the lever 15 is thus
pivoted on the elevator car 1 at fixing point 17. From
fixing point 16, the hoisting ropes 3 run upwards to a
diverting pulley 14 placed in the upper part of the
elevator shaft above the elevator car 1, from which
diverting pulley the ropes 3 go further downwards to a
diverting pulley 13 on the elevator car, and from this
diverting pulley 13 the ropes go upwards again to a
diverting pulley 12 fitted in the upper part of the
shaft above the car. From diverting pulley 12, the
ropes go further downwards to a diverting pulley 11
mounted on the elevator car. Having passed around this
pulley, the ropes go again upwards to a diverting pul-
ley 10 fitted in the upper part of the shaft, and hav-
ing passed around this pulley they go downwards again
to a diverting pulley 9 fitted on the elevator car.
After wrapping around this diverting pulley 9, the
hoisting ropes 3 go further upwards to the traction
sheave 5 of the drive machine 4 placed in the upper
part of the elevator shaft, having previously passed
via a diverting pulley 7 with only a "tangential con-
tact" with the ropes. This means that the ropes 3 go-
ing from the traction sheave 5 to the elevator car 1
pass via the rope grooves of diverting pulley 7 while
the deflection of the rope 3 caused by the diverting
pulley 7 is very small. It could be said that the
ropes 3 coming from the traction sheave 5 only touch
the diverting pulley 7 "tangentially". Such "tangen-
tial contact" serves as a solution damping the vibra-
tions of the outgoing ropes and it can be applied in
other roping solutions as well. The ropes pass around
the traction sheave 5 of the hoisting machine 4 along
the rope grooves of the traction sheave 5 . From the
traction sheave 5, the ropes 3 go further downwards to
diverting pulley 7, passing around it along the rope
grooves of the diverting pulley 7 and returning back
up to the traction sheave 5, over which they pass
along the rope grooves of the traction sheave. From
the traction sheave 5, the hoisting ropes 3 go further
downwards in "tangential contact" with diverting pul-
ley 7 past the elevator car 1 moving along guide rails
2, to a diverting pulley 8 placed in the lower part of
the elevator shaft, passing around it along the rope
grooves on it. From the diverting pulley 8 in the
lower part of the elevator shaft, the ropes go upwards
to a diverting pulley 18 on the elevator car, from
where the ropes 3 go further to a diverting pulley 19
in the lower part of the elevator shaft and further
back up to a diverting pulley 20 on the elevator car,
from where the ropes 3 go further downwards to a di-
verting pulley 21 in the lower part of the shaft, from
where they go further to a diverting pulley 22 on the
elevator car, from where the ropes 3 go further to a
diverting pulley 23 in the lower part of the elevator
shaft. From diverting pulley 23, the ropes 3 go fur-
ther to the lever 15 pivotally fixed to the elevator
car 1 at point 17, one end of the ropes 3 being im-
movably fastened to said lever 15 at point 24 at dis-
tance b from the pivot 17. In the case illustrated in
Fig. 1, the hoisting machine and the diverting pulleys
are preferably all placed on one and the same side of
the elevator car. This solution is particularly advan-
tageous in the case of a rucksack-type elevator, in
which case the above-mentioned components are disposed
behind the elevator car, in the space between the ele-
vator car and the back wall of the shaft. The hoisting
machine and the diverting pulleys may also be laid out
in other appropriate ways in the elevator shaft. The
roping arrangement between the traction sheave 5 and
the diverting pulley 7 is referred to as Double Wrap
roping, wherein the hoisting ropes are wrapped around
the traction sheave two and/or more times. In this
way, the contact angle can be increased in two and/or
more stages. For example, in the embodiment presented
in Fig. 1, a contact angle of 180° + 180°, i.e. 360 °
between the traction sheave 5 and the hoisting ropes 3
is achieved. The Double Wrap roping presented in the
figure can also be arranged in another way, e.g. by
placing diverting pulley 7 on the side of the traction
sheave 5, in which case, as the hoisting ropes pass
twice around the traction sheave, a contact angle of
180° + 90°, i.e. 270° is achieved, or by placing the
traction sheave in some other appropriate location. A
preferable solution is to dispose the traction sheave
5 and the diverting pulley 7 in such a way that the
diverting pulley 7 will also function as a guide of
the hoisting ropes 3 and as a damping pulley. Another
advantageous solution is to build a complete unit com-
prising both an elevator drive machine with a traction
sheave and one or more diverting pulleys with bearings
in a correct operating angle relative to the traction
sheave. The operating angle is determined by the rop-
ing used between the traction sheave an the diverting
pulley/diverting pulleys, which defines the way in
which the mutual positions and angle between the trac-
tion sheave and diverting pulley/diverting pulleys
relative to each other are fitted in the unit. This
unit can be mounted in place as a unitary aggregate in
the same way as a drive machine. In a preferred case,
the drive machine 4 may be fixed e.g. to a car guide
rail, and the diverting pulleys 7,10,12,14 in the up-
per part of the shaft are mounted on the beams in the
upper part of the shaft, which are fastened to the car
guide rails 2. The diverting pulleys 9,11,13,18,20,22
on the elevator car are preferably mounted on beams
disposed in the upper and lower parts of the car, but
they may also be secured to the car in other ways,
e.g. by mounting all the diverting pulleys on the same
beam. The diverting pulleys 8,19,21,23 in the lower
part of the shaft are preferably mounted on the shaft
floor. In Fig. 1, the traction sheave engages the rope
portion between diverting pulleys 8 and 9, which is a
preferable solution according to the invention. In a
preferable solution according to the invention, the
elevator car 1 is connected to the hoisting ropes 3 by
means of at least one diverting pulley from the rim of
which the hoisting ropes go upwards from both sides of
the diverting pulley, and at least one diverting pul-
ley from the rim of which the hoisting ropes go down-
wards from both sides of the diverting pulley, and in
which elevator the traction sheave 5 engages the por-
tion of the hoisting rope 3 between these diverting
pulleys. The roping between the traction sheave 5 and
diverting pulley 7 can also be implemented in other
ways instead of Double Wrap roping, such as e.g. by
using Single Wrap roping, in which case diverting pul-
ley 7 will not necessarily be needed at all, ESW rop-
ing (Extended Single Wrap), XW roping (X wrap) or some
other appropriate roping solution.
The drive machine 4 placed in the elevator shaft is
preferably of a flat construction, in other words, the
machine has a small thickness dimension as compared to
its width and/or height, or at least the machine is
slim enough to be accommodated between the elevator
car and a wall of the elevator shaft. The machine may
also be placed differently, e.g. by disposing the slim
machine partly or completely between an imaginary ex-
tension of the elevator car and a shaft wall. In the
elevator of the invention, it is possible to use a
drive machine 4 of almost any type and design that
fits into the space intended for it. For example, it
is possible to use a geared or gearless machine. The
machine may be of a compact and/or flat size. In the
suspension solutions according to the invention, the
rope speed is often high as compared to the speed of
the elevator, so it is possible to use even unsophis-
ticated machine types as the basic machine solution.
The elevator shaft is advantageously provided with
equipment required for the supply of power to the mo-
tor driving the traction sheave 5 as well as equipment
needed for elevator control, both of which can be
placed in a common instrument panel 6 or mounted sepa-
rately from each other or integrated partly or wholly
with the drive machine 4. A preferable solution is a
gearless machine comprising a permanent magnet motor.
The drive machine may be fixed to a wall of the eleva-
tor shaft, to the ceiling, to a guide rail or to some
other structure, such as a beam or frame. In the case
of an elevator with machine below, a further possibil-
ity is to mount the machine on the bottom of the ele-
vator shaft. Fig. 1 illustrates a preferred suspension
solution in which the suspension ratio of the divert-
ing pulleys above the elevator car and the diverting
pulleys below the elevator car is the same 7:1 suspen-
sion in both cases. To visualize this ratio in prac-
tice, it means the ratio of the distance traveled by
the hoisting rope to the distance traveled by the ele-
vator car. The suspension arrangement above the eleva-
tor car 1 is implemented by means of diverting pulleys
14,13,12,11,10,9 and the suspension arrangement below
the elevator car 1 is implemented by means of divert-
ing pulleys 23,22,21,20,19,18,8. Other suspension so-
lutions can also be used to implement the invention.
The elevator of the invention can also be implemented
as a solution comprising a machine room, or the ma-
chine may be mounted to be movable together with the
elevator. In the invention, the diverting pulleys con-
nected to the elevator car may be preferably mounted
on one and the same beam. This beam may be fitted on
top of the car, on the side of the car or below the
car, on the car frame or in some other appropriate
place in the car structure. The diverting pulleys may
also be fitted each one separately in appropriate
places on the car and in the shaft. The diverting pul-
leys placed above the elevator car in the elevator
shaft, preferably in the upper part of the elevator
shaft, and/or the diverting pulleys placed below the
elevator car in the elevator shaft, preferably in the
lower part of the elevator shaft, may also be fitted
e.g. on a common anchorage, such as e.g. a beam.
The function of the lever, 15 pivoted on, the elevator
car at point 17 in Fig. 1 is to eliminate rope elonga-
tions occurring in the hoisting rope 3. On the other
hand, it is essential to the operation and safety of
the elevator that a sufficient tension be maintained
in the lower rope portion, which refers to that part
of the hoisting rope which is below the elevator car.
By means of the lever arrangement 15 according to the
invention, the tensioning of the hoisting rope and the
compensation of rope elongation can be achieved with-
out using a prior-art spring or weight. By means of
the lever arrangement 15 of the invention, it is also
possible to implement the rope tensioning in such man-
ner that the ratio T1/T2 between the rope forces T1 and
T2 acting in different directions on the traction
sheave 5 can be kept at a desired constant value,
which may be e.g. 2. In connection with rope forces,
we can also speak of rope tensions. This constant ra-
tio can be varied by varying the distances a and b,
because T1/T2 = b/a. When odd suspension ratios are
used in the suspension of the elevator car, the lever
15 is pivoted on the elevator car, and when even sus-
pension ratios are used, the lever 15 is pivoted on
the elevator shaft.
Fig. 2 presents a diagrammatic illustration of the
structure of an elevator according to the invention.
The elevator is preferably an elevator without machine
room, with the drive machine 204 placed in the eleva-
tor shaft. The elevator shown in the figure is a trac-
tion sheave elevator with machine above and without
counterweight, with an elevator car 2 01 moving along
guide rails 2. The passage of the hoisting ropes 203
in Fig. 2 is similar to that in Fig. 1, but in Fig. 2
there is the difference that the lever 215 is immova-
bly pivoted on a wall of the elevator shaft at point
217. As the lever 215 is pivoted on the elevator
shaft, preferably on a wall of the elevator shaft, in-
stead of on the elevator car, this is a case of even
suspension ratio both in the rope portion above the
elevator car 1 and in the rope portion below it. The
suspension above the elevator car comprises the hoist-
ing machine 2 04 and diverting pulleys
209, 210, 211,212,213,214. The suspension below the ele-
vator car comprises diverting pulleys 208,218,219,
229,221,222,223. One end of the hoisting rope is fas-
tened to the lever 215 at point 216, which is at dis-
tance a from the pivot 217, while its other end is
fastened to the lever 215 at point 224, which is at
distance b from the pivot 217. Both in the rope por-
tion above the elevator car and in the rope portion
below it, the suspension ratio of the elevator car is
6:1.
Due to a high suspention ratio, the rope length of the
hoisting rope used in an elevator without counter-
weight is large. For example, in an elevator without
counterweight suspended with a suspension ratio of
10:1, in which the same suspension ratio 10:1 is used
both above and below the elevator car, and which ele-
vator has a hoisting height of 25 meters, the rope
length of the hoisting rope is about 270 meters. In
this case, as a result of variations in rope stress
and/or temperature, the length of the rope may change
by as much as about 50 cm. Therefore, the requirements
regarding compensation of rope elongation are also
greater. For the operation and safety of the elevator,
it is essential that the rope below the elevator car
be kept under a sufficient tension. This can not al-
ways be accomplished by using a spring or a simple
lever.
Fig. 3 presents a diagrammatic illustration of the
structure of an elevator according to the invention.
The elevator is preferably an elevator without machine
room, with the drive machine 3 04 placed in the eleva-
tor shaft. The elevator shown in the figure is a trac-
tion sheave elevator with machine above and without
counterweight, with an elevator car 3 01 moving along
guide rails 302. In Fig. 3, the lever solution used in
Fig. 1 and 2 has been replaced with two sheave-like
bodies, preferably sheaves 313 and 315, connected to
each other at point 314, where the tensioning sheaves
313,315 are fixedly secured to the elevator car 301.
Of the sheave-like bodies, the sheave 315 engaging the
hoisting rope portion below the elevator car has a di-
ameter larger than the diameter of the sheave 313 en-
gaging the hoisting rope portion above the elevator
car. The diameter ratio between the diameters of the
tensioning sheaves 313 and 315 determines the magni-
tude of the tensioning force acting on the hoisting
rope and therefore also the force of compensation of
hoisting rope elongations. In this solution, the use
of tensioning sheaves provides the advantage that the
structure compensates even very large rope elonga-
tions. By varying the diametric size of the tensioning
sheaves, it is possible to influence the magnitude of
the rope elongation to be compensated and the ratio
between the rope forces T1 and T2 acting on the trac-
tion sheave, which ratio can be rendered constant by
this arrangement. Due to a large suspension ratio or a
large hoisting height, the length of the rope used in
the elevator is large. For the operation and safety of
the elevator, it is essential that the hoisting rope
portion below the elevator car be kept under a suffi-
cient tension and that the amount of rope elongation
to be compensated be large. Often this can not be im-
plemented using a spring or a simple lever. With odd
suspension ratios above and below the elevator car,
the tensioning sheaves are immovably fitted in connec-
tion with the elevator car, and with even suspension
ratios the tensioning sheaves are immovably fitted to
the elevator shaft or some other corresponding loca-
tion which is not fixedly fitted to the elevator car.
The solution can be implemented using tensioning
sheaves as presented in Fig. 3 and 4, but the number
of sheave-like bodies used may vary; for example, it
is possible to use only one sheave with locations fit-
ted for hoisting rope fixing points differing in di-
ameter. It is also possible to use more than two ten-
sioning sheaves e.g. to allow the diameter ratio be-
tween the sheaves to be varied by only changing the
diameter of the tensioning sheaves.
In Fig. 3, the hoisting ropes run as follows. One end
of the hoisting ropes is secured to tensioning sheave
313, which sheave is immovably attached to sheave 315.
This set of sheaves 313,315 is fitted to the elevator
car at point 314. From sheave 313, the hoisting ropes
3 03 go upwards and encounter a diverting pulley 312
placed above the elevator car in the elevator car,
preferably in the upper part of the elevator shaft,
passing around it along rope grooves provided in the
diverting pulley 312. These rope grooves may be coated
or uncoated, e.g. with friction increasing material,
such as polyurethane or some other appropriate mate-
rial . From pulley 312, the ropes go further downwards
to a diverting pulley 311 on the elevator car, and
having passed around this pulley, the ropes go further
upwards to a diverting pulley 310 fitted in the upper
part of the shaft. Having passed around this diverting
pulley 310, the rope goes again downwards to a divert-
ing pulley 309 mounted on the elevator car, and having
passed around this pulley the hoisting ropes go fur-
ther upwards to a diverting pulley 307 preferably fit-
ted near the hoisting machine 304. Between diverting
pulley 307 and the traction sheave 304, the figure
shows X wrap roping, in which roping the hoisting rope
runs crosswise with the rope portion going upwards
from diverting pulley 3 07 to the traction sheave 3 05
and with the rope portion returning from the traction
sheave 305 to diverting pulley 307. Pulleys
313,312,311,310,309 together with the hoisting machine
form the suspension arrangement above the elevator
car, where the suspension ratio is the same as in the
suspension arrangement below the elevator car, this
suspension ratio being 5:1 in Fig. 3. From diverting
pulley 307, the ropes run further to a diverting pul-
ley 308 preferably fitted in place in the lower part
of the elevator shaft e.g. on a car guide rail 302 or
on the shaft floor or in some other appropriate place.
Having passed around diverting pulley 308, the hoist-
ing ropes 303 go further upwards to a diverting pulley
316 fitted in place on the elevator car, pass around
this pulley and then go further downwards to a divert-
ing pulley 317 in the lower part of the elevator
shaft, passing around it and returning to a diverting
pulley 318 fitted in place on the elevator car. Having
passed around diverting pulley 318, the hoisting ropes
3 03 go further downwards to a diverting pulley 319
fitted in place in the lower part of the elevator
shaft, passing around it and then going further up-
wards to the tensioning sheave 315 fitted in place on
the elevator car and immovably fitted to tensioning
sheave 313.
Fig. 4 presents a diagrammatic illustration of the
structure of an elevator according to the invention.
The elevator is preferably an elevator without machine
room, with a drive machine 404 placed in the elevator
shaft. The elevator shown in the figure is a traction
sheave elevator without counterweight and with machine
above, with an elevator car 401 moving along guide
rails 402. The passage of the hoisting ropes 403 in
Fig. 4 corresponds to that in Fig. 3 with the differ-
ence that in Fig. 4 the tensioning sheaves 413,415 are
fitted in place in the elevator shaft, preferably on
the bottom of the elevator shaft. As the tensioning
sheaves 413,415 are fitted in place in the elevator
shaft and not in connection with the elevator car,
this is a case of even suspension ratio both in the
rope portion above the elevator car 1 and in the rope
portion below it. In Fig. 4, the suspension ratio is
4:1. The end of the hoisting ropes 403 below the ele-
vator car 401 is fastened to the tensioning sheave 415
with a larger diameter while the end of the hoisting
ropes above the elevator car is fastened to the ten-
sioning sheave 413 with a smaller diameter. The ten-
sioning sheaves 413,415 are immovably fitted together
and they are secured to the elevator shaft via a
mounting piece 420. The suspension above the elevator
car comprises the hoisting machine and diverting pul-
leys 412,411,410,409,407. The suspension below the
elevator car comprises diverting pulleys
408,416,417,418,419. A set of tensioning sheaves (415,
413) as illustrated in Fig. 4 used as a compensating
system can also be advantageously mounted in place of
either diverting pulley 419 at the bottom of the
shaft, which pulley is preferably secured to the shaft
floor, or diverting pulley 412 in the upper part of
the shaft, which pulley is preferably secured to the
ceiling of the shaft. In this case, the number of di-
verting pulleys needed is one less than in the embodi-
ment presented in Fig. 4. Thus, in advantageous cases,
installing the elevator is also an easier and faster
operation.
Fig. 5 presents a diagrammatic illustration of the
structure of an elevator according to the invention.
The elevator is preferably an elevator without machine
room, with a drive machine 5 04 placed in the elevator
shaft. The elevator presented in the figure is a trac-
tion sheave elevator without counterweight and with
machine above, with an elevator car 5 01 moving along
guide rails 502. In elevators with a large hoisting
height, the elongation of the hoisting rope involves a
need to compensate the rope elongation, which has to
be done reliably within certain allowed limit values.
Using a set of rope force compensating sheaves 524 ac-
cording to the invention as presented in Fig. 5, a
very long movement is achieved for the compensation of
rope elongation. This permits the compensation of even
large elongations, which often can not be achieved us-
ing simple lever or spring solutions. The compensating
sheave arrangement according to the invention pre-
sented in Fig. 5 produces a constant ratio T1/T2 be-
tween the rope forces T1 and T2 acting on the traction
sheave. In the case illustrated in Fig. 5, the ratio
T1/T2 equals 2/1.
The passage of the hoisting ropes in Fig. 5 is as fol-
lows. One end of the hoisting ropes 503 is fastened to
diverting pulley 525, which diverting pulley has been
fitted to hang on the rope portion coming downwards
from diverting pulley 514. Diverting pulleys 514 and
525 together form a rope force compensating system
524, which in the case of Fig. 5 is a set of compen-
sating sheaves. From diverting pulley 514, the hoist-
ing ropes run further as described in connection with
the previous figures between diverting pulleys
512,510,507 fitted in place in the upper part of the
elevator shaft and diverting pulleys 513,511,509 fit-
ted in place on the elevator car, forming the suspen-
sion arrangement above the elevator car. Between the
hoisting machine 504 and the traction sheave 505, DW
suspension is used, which was already described in de-
tail in connection with Fig. 1. The roping between the
diverting pulley 507 and the traction sheave can also
be implemented using other appropriate roping solu-
tions, such as e.g. SW, XW or ESW suspension. From the
traction sheave, the hoisting ropes go further via di-
verting pulley 507 to a diverting pulley 508 placed in
the lower part of the elevator shaft. Having passed
around diverting pulley 508, the hoisting ropes run
between diverting pulleys 518,520,522 fitted in place
in the lower part of the shaft and diverting pulleys
519,521,523 fitted on the elevator car 501 in the man-
ner described in connection with the previous figures.
From diverting pulley 523, the hoisting ropes 503 go
further to a diverting pulley 525 comprised in the
rope force compensating sheave system 524 and fastened
to one end of the hoisting rope. Having passed around
diverting pulley 525 along its rope grooves, going
further to the anchorage 526 of the other end of the
rope in the elevator shaft or in some other appropri-
ate place. The suspension ratio of the elevator car
both above and below the elevator car is 6:1.
In the embodiment presented in Fig. 5, the rope force
compensating sheave system 524 compensates rope elon-
gations by means of diverting pulley 525. This divert-
ing pulley 525 moves through distance I, compensating
elongations of the hoisting ropes 503. The compensat-
ing distance I equals half the rope elongation of the
hoisting ropes. In addition, this arrangement produces
a constant tension across the traction sheave 505, the
ratio T1/T2 between the rope forces being 2/1. The rope
force compensating sheave system 524 can also be im-
plemented in other ways besides that described in the
example, e.g. by using more complex suspension ar-
rangements with the rope force compensating sheaves,
for example by using different suspension ratios be-
tween the diverting pulleys in the compensating sheave
system.
Fig. 6 presents another implementation for the compen-
sation of rope elongations using a compensating device.
In Fig. 6, the passage of the ropes and the suspension
ratio in the portions above and below the elevator car
are identical to those in Fig. 5 as described above.
The hoisting ropes 603 run between diverting pulleys
609,611,613 mounted on the elevator car and diverting
pulleys 610,612,614 in the upper part of the elevator
shaft and the traction sheave 605 in the manner pre-
sented in Fig. 5, and the ropes go further from the
traction sheave 605 to the lower part of the elevator
shaft to traction sheave 608, and having passed around
it they run further between the diverting pulleys
618,620,622 fitted on the elevator car and the divert-
ing pulleys 619,621,623 fitted in the lower part of
the elevator shaft as described in connection with Fig.
5. The suspension ratio of the elevator car in the por-
tions above and below the elevator car is 6:1. The ele-
vator presented in Fig. 6 differs from the situation
illustrated in Fig. 5 in respect of the compensating
device 624. Fig. 6 presents a different roping arrange-
ment according to the invention in the set of compen-
sating sheaves 624 of the compensating device. In the
set of compensating sheaves, one end 629 of the hoist-
ing ropes 603 is immovably fitted to the elevator
shaft, from which point the hoisting ropes go to the
traction sheave 625, pass around it and go further to a
diverting pulley 614 possibly fitted in place in the
upper part of the elevator shaft, from where they run
further in the manner described above to the traction
sheave 605. Diverting pulley 625 is fixedly fitted in
conjunction with another diverting pulley 626. These
diverting pulleys 626,625 may be placed e.g. on the
same shaft or they may be connected to each other by a
bar or in some other appropriate manner. After passing
around diverting pulley 623, the portion of the hoist-
ing ropes 603 below the elevator car comes to the di-
verting pulley 626 of the compensating device 624, this
pulley being connected to diverting pulley 62 5 in the
manner described above. Having passed around diverting
pulley 626, the hoisting ropes 603 go further to a di-
verting pulley 627 immovably fitted in place in the
shaft and forming part of the compensating system 624.
Having passed around the diverting pulley 627, the
hoisting ropes 603 go further to an anchorage 628, to
which the other end of the hoisting ropes is immovably
secured. This anchorage 628 is on diverting pulley 625
or fixedly connected to it. Using this roping arrange-
ment in the compensating device 624, a constant ratio
T1/T2 = 3/2 between the rope forces T1 and T2 is
achieved. Using this roping arrangement, it is possible
to implement SW roping on the traction sheave, in other
words, the diverting pulley 507 shown in Fig. 5 is not
necessarily needed at all. SW roping can be used on the
traction sheave because the illustrated roping arrange-
ment in the compensating device 624 minimizes the re-
quired friction force on the traction sheave and per-
mits small rope forces T1 and T2. However, the diverting
pulley 507 presented in Fig. 5 can be used if desirable
e.g. to provide a tangential contact with the hoisting-
ropes as described in connection with the previous fig-
ures. In the compensating device 624, the roping and
the number of diverting pulleys may also vary in ways
other than those described in this Fig. 6. Via the rop-
ing suspension ratios in the compensating device 62 4,
the T1/T2 ratio can be maintained at a desired constant
magnitude. In Fig. 6, the compensation of rope elonga-
tion is effected by means of diverting pulley 62 5 and
the diverting pulley 62 6 fixedly fitted to it. The rope
elongation compensating distance in the compensating
device is the shorter the greater is the suspension ra-
tio within it.
Fig. 7 presents an embodiment of the invention in which,
the suspension ratio of the roping is 1:1. In the ele-
vator presented in Fig. 7, the compensation of rope
elongation is implemented using a lever 715, which
lever 715 functions as a rope force compensating device
and is immovably pivoted on the elevator car 701. The
rope forces are compensated and a constant ratio be-
tween the rope forces T1 and T2 is achieved in the man-
ner described in connection with Fig. 1, which yields
the T1/T2 ratio as T1/T2 = b/a, which is independent of
the magnitude of the load. The example of an embodiment
of the elevator of the invention presented in Fig. 7
can be implemented using e.g. commonly used conven-
tional ropes having a diameter of 8 mm in an elevator
for a nominal load of 4 persons, i.e. about 700 kg. In
this elevator, the T1/T2 ratio is 1.5/1 and it uses a
traction sheave having a diameter of 320 mm and conven-
tional undercut grooves, and the mass of the elevator
car is 700 kg. In this case, the force T1 lifting the
elevator car upwards is 1.5 times the force required
for lifting the weight of the elevator car and its
load, and the force T2 acting downwards on the elevator
car is the force required for lifting the weight of the
elevator car and the load. This example is not ideal as
it leads to an unnecessarily high rope tension relative
to the load. By increasing the suspension ratio, it is
possible to reduce this rope tension. The elevator of
the invention may be provided with a geared machine and
it can be constructed e.g. according to Fig. 7 with 1:1
roping.
Fig. 8 presents an elevator according to the invention
in which a suspension ratio of 2:1 is used in the rop-
ing portion 803 of the hoisting ropes above and below
the elevator car 801 and DW roping between the traction
sheave 805 and the diverting pulley 807. Compensation
of rope elongations and constant rope forces are imple-
merited using a rope elongation compensating device as
presented in Fig. 5, which produces a rope force ratio
of T1/T2 =2/1 while the compensating distance traveled
by the diverting pulley 82 5 equals half the magnitude
of the rope elongation.
Fig. 9 presents an embodiment of the invention for com-
pensating rope elongations and maintaining a constant
rope fore ratio. In Fig. 9, the passage of the hoisting
ropes is as described above in connection with Fig. 6,
where the suspension ratio of the elevator car above
and below the elevator car is 6:1. The passage of the
hoisting ropes in Fig. 9 differs from the situation
shown in Fig. 6 in that the ropes go downwards from di-
verting pulley 914 to diverting pulley 924, and also in
respect of the compensating system. In addition, one
end of the hoisting ropes 903 is immovably fixed to the
elevator shaft at point 923 before the ropes go to di-
verting pulley 922. In this figure, the compensation of
rope elongation is implemented by fastening diverting
pulley 908 to the second end of the hoisting ropes 903
at point 926. The elongation of the hoisting ropes is
compensated by allowing diverting pulley 9 08 to move
upwards or downwards through a distance equal to half
the rope elongation, thus compensating the rope elonga-
tion. In the system illustrated in Fig. 9, the compen-
sation of rope elongations and a constant ratio of rope
forces are implemented on the same principle as in the
situation represented by Fig. 5, where the rope force
ratio is T1/T2 and the compensating distance through
which diverting pulley 908 moves equals half the magni-
tude of the rope elongation. The compensating system
presented in Fig. 9 can be implemented by means of any
one of the diverting pulleys 908,919,921 in the lower
part of the elevator shaft by fastening the second end
of the hoisting ropes to the diverting pulley in gues-
tion, as described above in connection with diverting
pulley 9 08.
When the elevator car is suspended with a small suspen-
sion ratio, such as e.g. 1:1, 1:2, 1:3 or 1:4, divert-
ing pulleys of a large diameter and hoisting ropes of a
large thickness can be used. Below the elevator car it
is possible to use smaller diverting pulleys if neces-
sary, because the tension in the hoisting ropes is
lower than in the portion above the elevator car, al-
lowing smaller hoisting rope deflection radiuses to be
used. In elevators with a small space below the eleva-
tor car, it is advantageous to use diverting pulleys of
small diameter in the rope portion below the elevator
car. Since by using the rope force compensating system
of the invention a constant tension in the hoisting
rope portion below the elevator car can be achieved
that is smaller by the ratio T1/T2 than the tension in
the rope portion above the elevator car, this makes it
possible to reduce the diameters of the diverting pul-
leys in the rope portion below the elevator car without
substantially impairing the service life of the hoist-
ing ropes. For example, the ratio between the diameter
D of the diverting pulley to the diameter d of the rope
used may be D/d
be only D/d = 25...3 0, while the ratio of the diameters
of the hoisting rope portion and diverting pulleys
above the elevator car is D/d = 40. The use of divert-
ing pulleys of a smaller diameter allows the space be-
low the elevator car to be reduced to a very small
size, which may preferably be only 200 mm.
A preferred embodiment of the elevator of the invention
is an elevator without machine room and with machine
above, in which the drive machine has a coated traction
sheave, and which elevator has thin hoisting ropes of a
substantially round cross-section. In the elevator, the
contact angle between the hoisting ropes and the trac-
tion sheave is greater than 18 0°. The elevator com-
prises a unit with a mounting base on which are fitted
a drive machine, a traction sheave and a diverting
pulley ready fitted at a correct angle relative to the
traction sheave. The unit is secured to the elevator
guide rails. The elevator is implemented without coun-
terweight with a suspension ratio of 9:1 so that both
the roping suspension ratio above the elevator car and
the roping suspension ratio below the elevator car is
9:1, and that the roping of the elevator runs in the
space between one of the walls of the elevator car and
the wall of the elevator shaft. The solution for com-
pensating the rope elongations of the elevator rope
comprises a set of compensating sheaves, which creates
a constant ratio T1/T2=2:1 between the forces T1 and T2.
With the compensating sheave system used, the required
compensating distance equals half the magnitude of the
rope elongation.
Another preferred embodiment of the elevator of the
invention is an elevator without counterweight in
which the suspension ratio above and below the eleva-
tor car is 10:1. In this embodiment, conventional ele-
vator hoisting ropes are used, which preferably are
ropes of a diameter of 8 mm, and a traction sheave
which is made of cast iron at least in the area of the
rope grooves. The traction sheave has undercut rope
grooves and a diverting pulley is used to adjust the
rope contact on the traction sheave to 180° or more.
When conventional 8-mm ropes are used, the traction
sheave diameter is preferably 340 mm. The diverting
pulleys used are large rope sheaves which, when con-
ventional 8-mm hoisting ropes are used, have a diame-
ter of 320,330,340 mm or even more. The rope forces
are kept constant so that the ratio T1/T2 between them
is 3/2.
Fig. 10a and 10b present another example situation, in
which a roped elevator with counterweight as shown in
Fig. 10a has been replaced with or modernized into a
roped elevator without counterweight according to the
invention as presented in Fig. 10b. The elevator pre-
sented in Fig. 10a is a roped elevator with a counter-
weight 1003, in which elevator the counterweight 1003
and the counterweight guide rails 1004 are placed, as
seen from the door opening 1006, behind the elevator
car 1001 moving along guide rails 1002, in the eleva-
tor shaft 1007 in the space between the elevator car
1001 and the shaft wall 1005. Fig. 10b shows how the
space required by the counterweight 1003 and its guide
rails 1004 has been eliminated in the elevator shaft
1007 and how the space thus freed up can be utilized
for the elevator car 1001 if necessary. This provides
the possibility to install a larger elevator car in
the same shaft. In the case of a conventional passen-
ger elevator as illustrated in Fig. 10b, it is possi-
ble to obtain e.g. about 20 - 25 cm or even more of
additional car depth when the elevator presented in
Fig. 10a is replaced with or modernized into an eleva-
tor without counterweight as shown in Fig. 10b.
Fig. 10c and 10d present another example situation, in
which a roped elevator with counterweight as shown in
Fig. 10c has been replaced with or modernized into a
roped elevator without counterweight according to the
invention as presented in Fig. 10d. in the roped ele-
vator with counterweight presented in Fig. 10a, the
counterweight 1003 and its guide rails 1004 are placed
on one side of the elevator car 1001 as seen from the
door opening 1006. Fig. 10d shows how, according to
the invention, the elevator in Fig. 10c has been re-
placed with or modernized into a roped elevator with-
out counterweight according to the invention. The
space freed up in the elevator shaft 1007 by removing
the counterweight 1003 and its guide rails 1004 can be
utilized for the elevator car 1001, allowing the width
of the elevator car 1001 to be increased. In the case
of a conventional passenger elevator as illustrated in
Fig. 10d, it is possible to obtain e.g. about 10 - 20
cm or even more of additional car width when the ele-
vator presented in Fig. 10c is replaced with or mod-
ernized into an elevator without counterweight as
shown in Fig lOd.
Fig. 10e and 10f present a third example situation, in
which a side-lifting hydraulic elevator as shown in
Fig. 10e has been replaced with or modernized into an
elevator without counterweight according to the inven-
tion as presented in Fig. 10f. The hydraulic elevator
in Fig. 10e comprises a hydraulic cylinder 1009 be-
longing to the hydraulic lifting apparatus, a divert-
ing pulley 1008 comprised in the hoisting rope system,
and its possible guide rails are placed on one side on
the elevator car 1001 as seen from the door opening
1006. In the situation illustrated in Fig. lOe, the
elevator car 1001 is hoisted along guide rails 1002
from one side on the elevator car, but the hoisting
function may also be implemented in other ways. The
hydraulic lifting function to be replaced or modern-
ized may also consist of a system with lifting force
applied from below the elevator car. Fig. 10f illus-
trates how, according to the invention, the elevator
in Fig. 10e is replaced with or modernized into a
roped elevator without counterweight according to the
invention. The space freed up in the elevator shaft
1007 by removing the hydraulic lifting apparatus and a
possible counterweight can be utilized for the eleva-
tor car 1001, allowing the width of the elevator car
1001 to be increased. In the case of a conventional
passenger elevator as illustrated in Fig. 10f, it is
possible to obtain e.g. about 5-15 cm or even more
of additional car width when the elevator presented in
Fig. 10e is replaced with, or modernized into an eleva-
tor without counterweight as shown in Fig 10f.
It is obvious to the person skilled in the art that
different embodiments of the invention are not limited
to the examples described above, but that they may be
varied within the scope of the claims presented below.
For instance, the number of times the hoisting ropes
are passed between the upper part of the elevator
shaft and the elevator car and between the elevator
car and the diverting pulleys below it is not a very
decisive question as regards the basic advantages of
the invention, although it is possible to achieve some
additional advantages by using multiple rope passages.
In general, applications are so implemented that the
ropes go to the elevator car from above as many times
as from below, so that the suspension ratios of di-
verting pulleys going upwards and diverting pulleys
going downwards are the same. It is also obvious that
the hoisting ropes need not necessarily be passed un-
der the car. In accordance with the examples described
above, the skilled person can vary the embodiment of
the invention, while the traction sheaves and rope
pulleys, instead of being coated metal pulleys, may
also be uncoated metal pulleys or uncoated pulleys
made of some other material suited to the purpose.
It is further obvious to the person skilled in the art
that the traction sheaves and rope pulleys of metallic
or some other appropriate material that are used in
the invention, functioning as diverting pulleys and
coated with a non-metallic material at least in the
area of their grooves, may have a coating made of e.g.
rubber, polyurethane or some other material suited to
the purpose.
It is also obvious to the person skilled in the art
that the elevator car and the machine unit may be laid
out in the cross-section of the elevator shaft in a
manner differing from the lay-out described in the ex-
amples. Such a different lay-out might be e.g. one in
which the machine is located behind the car as seen
from the shaft door and the ropes are passed under the
car diagonally relative to the bottom of the car.
Passing the ropes under the car in a diagonal or oth-
erwise oblique direction relative to the form of the
bottom provides an advantage when the suspension of
the car on the ropes is to be made symmetrical rela-
tive to the center of mass of the elevator in other
types of suspension lay-out as well.
It is further obvious to the person skilled in the art
that the equipment required for the supply of power to
the motor and the equipment needed for elevator con-
trol can be placed elsewhere than in connection with
the machine unit, e.g. in a separate instrument panel,
or equipment needed for control can be implemented as
separate units which can be disposed in different
places in the elevator shaft and/or in other parts of
the building. It is likewise obvious to the skilled
person that an elevator applying the invention may be
equipped differently from the examples described
above. It is further obvious to the skilled person that
the elevator of the invention can be implemented using
almost any type of flexible hoisting means as hoisting
ropes, e.g. flexible rope of one or more strands, flat
belt, cogged belt, trapezoidal belt or some other type
of belt applicable to the purpose. It is likewise obvi-
ous to the skilled person that the replacement or mod-
ernization according to the invention of an elevator
with a traction sheave elevator without counterweight
according to the invention can also be implemented in
the case of drum elevators, screw-driven elevators or
elevators having a hoisting function based on almost
any other technique.
It is also obvious to the skilled person that, instead
of using ropes with a filler, the invention may be im-
plemented using ropes without filler, which are either
lubricated or unlubricated. Zn addition, it is also
obvious to the person skilled in the art that the
ropes may be twisted in many different ways.
It is also obvious to the person skilled in the art
that the elevator of the invention can be implemented
using different roping arrangements between the trac-
tion sheave and the diverting pulley/diverting pulleys
to increase the contact angle a than those described as
examples. For example, it is possible to dispose the
diverting pulley/diverting pulleys, the traction sheave
and the hoisting ropes in other ways than in the roping
arrangements described in the examples. It is also ob-
vious to the skilled person that, in the elevator of
the invention, the elevator may also be provided with a
counterweight, in which case the counterweight has e.g.
a weight below that of the car and is suspended by a
separate roping arrangement.
Due to the bearing resistance of the rope pulleys used
as diverting pulleys and to the friction between the
ropes and the rope sheaves and possible losses occur-
ring in the compensating system, the ratio between the
rope tensions may deviate somewhat from the nominal
ratio of the compensating system. Even a deviation of
5% will not involve any significant disadvantage be-
cause in any case the elevator must have a certain in-
built robustness.
WE CLAIM :
1. An elevator, in which elevator the elevator car is suspended by means of
hoisting ropes consisting of a single rope or several parallel ropes, said elevator
having a traction sheave which moves the elevator car by means of the hoisting
ropes, characterized in that the elevator has rope portions of the hoisting ropes
going upwards and downwards from the elevator car, and the rope portions going
upwards from the elevator car are under a first rope tension (T1) which is greater
than a second rope tension (T2), which is the rope tension of the rope portions
going downwards from the elevator car, and that the elevator has been built in
place of an earlier elevator mounted in an elevator shaft or equivalent or by
making modifications in the earlier elevator, the arrangement being such that the
elevator roping is provided with a compensating system for maintaining a
substantially constant ratio (T1/T2) between the rope forces acting in upward and
downward directions.
2. An elevator as claimed in claim 1, wherein the earlier elevator is a
hydraulically lifting elevator.
3. An elevator as claimed in claim 1, wherein the earlier elevator is traction
sheave elevator.
4. An elevator as claimed in any one of the preceding claims, wherein the
elevator car of the elevator has a larger floor area than the earlier elevator.
5. An elevator as claimed in any one of the preceding claims, wherein the
elevator is an elevator without counterweight.
6. An elevator as claimed in any one of the preceding claims, wherein the
elevator has a compensating mechanism, and that the compensating
mechanism is preferably a lever, a set of tensioning sheaves or compensating
sheaves.
7. An elevator as claimed in any one of the preceding claims, wherein the
elevator has a compensating mechanism and that the compensating
mechanism comprises one and/or more diverting pulleys.
8. An elevator as claimed in any one of the preceding claims, wherein the
continuous contact angle between the traction sheave and the hoisting ropes
is at least 180°.
9. An elevator as claimed in any one of the preceding claims, wherein the
hoisting ropes used are high-strength hoisting ropes.
10. An elevator as claimed in any one of the preceding claims, wherein the
hoisting ropes have diameters smaller than 8 mm, preferably between 3-5
mm.
11. An elevator as claimed in any one of the preceding claims, wherein the
hoisting machine is particularly light in relation to the load.
12. An elevator as claimed in any one of the preceding claims, wherein the
traction sheave is coated with polyurethane, rubber or some other frictional
material suited to the purpose.
13. An elevator as claimed in any one of the preceding claims, wherein the
traction sheave, at least in the area of the rope grooves, is made of metal,
preferably cast iron, and preferably has undercut rope grooves.
14. An elevator as claimed in any one of the preceding claims, wherein the D/d
ratio of the diverting pulleys below the elevator car is below 40.
15. A method of forming an elevator in place of an earlier elevator mounted in an
elevator shaft or equivalent or by making modifications in the earlier elevator,
said method involving the steps of:
replacing the hoisting function of the earlier elevator by a hoisting function
comprising a set of hoisting ropes, said set of hoisting ropes having one rope
or a plurality of parallel ropes, and an elevator machine driving the hoisting
ropes;
connecting the elevator car of the elevator to be formed to the hoisting ropes
such that the elevator has rope portions going downwards and upwards from
the elevator car; and
providing the elevator roping with a compensating system for maintaining a
substantially constant ratio (T1/T2) between the rope forces acting in upward
and downward directions.
16. A method as claimed in claim 15, wherein the replacing hoisting function is
installed in place of a hydraulic hoisting function.
17. A method as claimed in claim 15, wherein the replacing hoisting function is
installed in place of a traction sheave-operated hoisting function comprising a
counterweight.
18. A method as claimed in claim 15, wherein the replacing hoisting function is
installed in place of a hoisting function implemented using a drum, a screw or
another corresponding hoisting function.
19. A method as claimed in claim 15, wherein the equipment comprised in the
hoisting function of the earlier elevator is removed from the elevator shaft or
equivalent.
20. A method as claimed in claim 15, wherein a replacing elevator car of a size
larger than the earlier elevator car is formed in the elevator shaft or
equivalent.
An elevator built in place of an earlier elevator in an elevator shaft or
equivalent is disclosed. Int he elevator, the elevator car is suspended by means of
hoisting ropes (3) consisting of a single rope of several parallel ropes. The
elevator has a traction sheave (5) which moves the elevator car by means of the
hoisting ropes (3). The elevator has rope portions of the hoisting ropes going
upwards and downwards from the elevator car, and the rope portions going
upwards from the elevator car are under a first rope tension (T1) which is greater
than a second rope tension (T2), which is the ope tension of the rope portion
going downwards from the elevator car, and the elevator has been built in place of
an earlier elevator mounted in the elevator shaft or equivalent or by making
modifications in the earlier elevator.